Snapping to faces problem, they snap to the inside of the item instead of the outside
This could be a problem of the normals being facing inside the mesh. Select all the faces and recalculate normals (provided all normals are facing inside). Then try snapping to the face.

The operator for recalculating normals is under the view header mesh menu. The hotkey is also displayed in the menu items.

Mesh -> Normals -> Recalculate Inside/Outside and Flip Normals

In case some of the faces only have normals facing inside, then select those faces and flip the normals.